1675: French mathematician Gilles de Roberval, who invented the Roberval balance weighing scale, died. 1811: Isaac Singer, inventor of the continuous-stitch sewing machine, was born. 1873: Farmer Joseph Glidden applied for a patent on barbed wire. 1904: New York City Subway opened with 9.1 miles of track running from City Hall to 145th Street. 1920: Pittsburgh radio station KDKA received its broadcast license & call letters. 1927: The first newsreel featuring sound was released in New York. 1938: Du Pont announced "nylon" as the name for its new synthetic yarn. 1943: The first women Marines reported for duty at Camp Pendleton. 1961: The first Saturn I heavy launch vehicle made an unmanned test launch. 1997: Dow Jones Industrial Average crashed a record 554 points to 7161. 2004: A total lunar eclipse occurred. 2005: IBM's Blue Gene/L system set a new world computing record of 280.6 teraflops.